i will try to find a heleberg from a friend and report back.

i found that some old european tubas are small bore and they fit a denis wick without the L in the name...i will order a similar one i think it will fit my new-old tuba

I tried a Denis Wick 2XL which went in halfway up the shank. I think the moat is a normal position (about 2cm out of 4cm possible).
The entrance of the tuba has an opening of ~14.2mm

Hello, I have a Perantucci PT50+ mouthpiece ... I recently acquired an old BB Tuba B&S 3/4, but apparently with a smaller entrance. The mouthpiece enters with 1/3 of the shank. Could this be a problem?
Thanks!

I apologize if such a topic exists.

Greetings!